Theory of anisotropic diamagnetism, local moment magnetization and carrier spin-polarization in Pb1−x Eu x Te

Abstract

We present theoretical analyses of anisotropic lattice diamagnetism, magnetization due to magnetic ions and carrier spin-polarization in the diluted magnetic semiconductor, Pb 1 x Eu x Te. The lattice diamagnetism results from orbital susceptibility due to inter band effects and spin-orbit contributions. The spin-orbit contribution is found to be dominant. However, both the contributions show pronounced anisotropy. With increase in x, the diamagnetism decreases. We consider contributions from randomly distributed isolated magnetic ions and clusters of pairs and triads for the local moment magnetization. The isolated magnetic-ion contribution is the dominant one. We calculate the magnetization for two typical magnetic ion concentrations: x 0 03 and x 0 06. Temperature dependence of the magnetization is also considered. Apart from lattice and localized magnetic ions, the carrier contribution to the spin-density is also calculated for a carrier density of p 10 18 cm 3 . The relative spin-density of carriers increases with increase in the magnetic field strength and magnetic ion concentration. The agreement with experiment where available is reasonably good.

Semiconductor magnetism: excitements and promises

“…On the other hand, semiconductors were not considered earlier as fashionable materials for research in magnetism, due presumably to the lack of exciting physics and possibilities for technologically useful applications. There were of course some studies on diamagnetism [4][5][6][7][8][9] and paramagnetism as related to the nuclear magnetic study of the Knight shift [10][11][12] and the chemical shift [13] involving orbital magnetism, in semiconductors.…”

From Diamagnetism to Dilute Magnetism in Semiconductors

“…There were of course some studies on diamagnetism [4][5][6][7][8][9] and paramagnetism as related to the nuclear magnetic study of the Knight shift [10][11][12] and the chemical shift [13] involving orbital magnetism, in semiconductors. On the other hand, semiconductors were not considered earlier as fashionable materials for research in magnetism, due presumably to lack of exciting physics and possibilities for technologically useful applications.…”